Objective To investigate the effects of estrogen replacement therapy on the serum nitric oxide and endothelin-1 level of ovariectomized rat.Methods The ovariectomized animal model and estrogen replacement therapy rat were established,thirty female rats were randomly divided into three groups:group A,ovariectomy;group B,ovariectomy plus estrogen replacement therapy;group C,sham-ovariectomy.The rats were killed after two months.The serum nitric oxide and endothelin-1 level were determined.Results In group A,the serum nitric oxide level was lower as compared with group C,but the serum endothelin-1 level was higher than those in group C.In group B,the serum nitric oxide level was higher and the serum endothelin-1 level was lower than those in group A.Conclusions Estrogen could modulate the productions of the nitric oxide and the endothelin-1 in the vascular endotheliocytes and improve the function of the vascular endothelial cells,which may be a bases of the benificial effect of estrogen in the prevention of atherosclerosis.

OBJECTIVE:To establish a method for simultaneous determination of 6 residual organic solvents in aprepitant raw material as methanol,ethanol,acetone,isopropyl alcohol,methyl tert-butyl ether and tetrahydrofuran.METHODS:Headspace capillary gas chromatography was adopted.The determination was performed on DB-624 capillary column using temperature programming.The temperature of injector port was 180 ℃,and flame ionization detector was used with temperature of 260 ℃.Nitrogen was used as carrier gas with flow rate 3.0 mL/min.The spilt ratio was 5 ∶ 1,and head-space injection volume was 1.0 mL.The head-space equilibrium temperature was set at 80 ℃,and equilibrium time was 40 min.RESULTS:The linear ranges of methanol,ethanol,acetone,isopropyl alcohol,methyl tert-butyl ether,tetrahydrofuran were 6.052-605.232 μ g/mL (r=0.999 9),9.987-998.718 μg/mL(r=0.999 9),9.998-999.768 μg/mL(r=0.999 8),9.986-998.634 μg/mL(r=0.999 9),9.991-999.090 μg/mL (r=0.999 7),1.461-146.133 μg/mL(r=0.999 5),respectively.The limits of quantitation were 1.782 1,2.079 0,0.749 8,1.777 8,0.223 1,0.607 0 μg/mL;the limits of detection were 0.594 0,0.693 0,0.249 9,0.592 6,0.074 4,0.202 3 μg/mL,respectively.RSD of precision test was lower than 2.0％.Only acetone and isopropyl alcohol were detected in stability test and reproducibility tests,RSD＜2.0％.Their recoveries were 99.34-100.75％ (RSD=0.52％,n=9),98.20％-100.24％ (RSD=0.69％,n=9),98.07％-100.07％ (RSD=0.84％,n=9),99.86％-101.32％ (RSD=0.58％,n=9),97.87％-104.02％ (RSD=2.13％,n=9),98.26 ％-100.58 ％ (RSD =0.75 ％,n =9),respectively.CONCLUSIONS:The established method is simple,accurate and reproducible,and can be used for simultaneous determination of 6 residual organic solvents in aprepitant raw material.

Rutin,a flavonoid found in fruits and vegetables,is a potential anticancer compound with strong anti-cancer activity.Therefore,electrochemical sensor was developed for the detection of rutin.In this study,CoWO4 nanosheets were synthesized via a hydrothermal method,and porous carbon(PC)was prepared via high-temperature pyrolysis.Successful preparation of the materials was confirmed,and character-ization was performed by transmission electron microscopy,scanning electron microscopy,and X-ray photoelectron spectroscopy.A mixture of PC and CoWO4 nanosheets was used as an electrode modifier to fabricate the electrochemical sensor for the electrochemical determination of rutin.The 3D CoWO4 nanosheets exhibited high electrocatalytic activity and good stability.PC has a high surface-to-volume ratio and superior conductivity.Moreover,the hydrophobicity of PC allows large amounts of rutin to be adsorbed,thereby increasing the concentration of rutin at the electrode surface.Owing to the syn-ergistic effect of the 3D CoWO4 nanosheets and PC,the developed electrochemical sensor was employed to quantitively determine rutin with high stability and sensitivity.The sensor showed a good linear range(5-5000 ng/mL)with a detection limit of O.45 ng/mL.The developed sensor was successfully applied to the determination of rutin in crushed tablets and human serum samples.

Objective:To explore the value of octreotide suppression test(OST) in predicting the efficacy of somatostatin receptor ligands(SRLs) in the treatment of active acromegaly.Methods:The clinical data of 76 patients with active acromegaly from 2011 to 2020 was retrospectively analyzed. OST was carried out as follows: After an overnight fasting and baseline sampling of growth hormone(GH), 100 μg octreotide was subcutaneously injected, and sampling for GH was obtained every 2 hours for 8 hours. All patients were treated with SRLs for at least 3 months. A good GH response is defined as a post-treatment random GH<1 μg/L or >80% fall compared with the baseline GH. A good insulin-like growth factor Ⅰ(IGF-Ⅰ) response is defined as IGF-Ⅰ<1.3 upper limit of normal(ULN) or >50% reduction compared with the baseline. If both GH and IGF-Ⅰ fulfill the criteria of a good response, it is defined as a good GH and IGF-Ⅰ response.Results:The baseline level of GH during OST was 15.00(6.38, 34.20) μg/L, the median time to reach the nadir GH was(3.65±1.65) hours, and the nadir GH level was 1.47(0.50, 4.19) μg/L. The median GH suppression rate was 89.12%(72.71%, 95.09%). When the cutoff value of GH suppression rate in predicting a good GH response was 89.32%, the area under the curve(AUC) was 0.74, with a sensitivity of 81.80% and specificity of 66.00%. When the cutoff value of GH suppression rate in predicting a good IGF-Ⅰ response was 93.14%, the AUC was 0.64, with a sensitivity of 50.00% and specificity of 75.60%. When the GH suppression rate was 90.71%, the AUC was 0.78, with the sensitivity of 83.30% and specificity of 70.00% in predicting a good GH and IGF-Ⅰ response. Compared with GH/IGF-Ⅰ non-responders, GH/IGF-Ⅰ responders displayed lower nadir GH during OST, higher GH suppression rate and IGF-Ⅰ reduction rate, and lower ratio of IGF-1 to ULN( P<0.05). Conclusion:GH suppression rate during the OST is a valuable predictor to evaluate the efficacy of SRLs in patients with acromegaly, with the highest sensitivity and specificity when the cutoff value is 90.71%.

We developed a high-efficiency microfluidic chip for extracting exosomes from human plasma. We collected peripheral blood from normal human, designed and fabricated a microfluidic chip based on nanoporous membrane and agarose gel electrophoresis to isolate exosomes. The extracted exosomes were characterized by transmission electron microscopy, nanosight and Western blotting, the morphology, concentration and particle size of exosomes were identified and analyzed. Meanwhile, we used ultracentrifugation and microfluidic chip to isolate exosomes separately. The particle size and concentration of the exosomes extracted by two methods were compared and analyzed, and their respective extraction efficiency was discussed. Finally, the expression level of miRNA-21 in exosomes was analyzed by RT-PCR. The microfluidic chip isolated (in 1 hour) high-purity exosomes with size ranging from 30-200 nm directly from human plasma, allowing downstream exosomal miRNA analysis. By comparing with ultracentrifugation, the isolation yield of microfluidic chip was 3.80 times higher than ultracentrifugation when the volume of plasma sample less than 100 μL. The optimized parameters for exosome isolation by gel electrophoresis microfluidic chip were: voltage: 100 V; concentration of agarose gel: 1.0%; flow rate of injection pump: 0.1 mL/h. The gel electrophoresis microfluidic chips could rapidly and efficiently isolate the exosomes, showing great potential in the research of exosomes and cancer biomarkers.
Exosomes ; Humans ; MicroRNAs/genetics* ; Microfluidics ; Plasma ; Ultracentrifugation